[sadra2003]

Originally Posted by wyldckat

Greetings Svensen,

There are a few boundary conditions that demonstrate how lookup tables can be used. Using lookup tables as OpenFOAM already does, would ensure that the bug is not coming from a possibly flawed implementation of the lookup mechanism you currently have implemented.

The boundary "src/finiteVolume/fields/fvPatchFields/derived/uniformFixedValue" has such an example:

1. The lookup table object is defined like this in the header file ".H":
   

   autoPtr<Function1<Type>> uniformValue_;

   • In your case:
     

     autoPtr<Function1<scalar>> visc;

2. Constructed like this:
   

   uniformValue_(Function1<Type>::New("uniformValue", dict))

   • In your case:
     

     visc(Function1<scalar>::New("viscTable", dict))

     Then the entry "viscTable" needs to be in "transportProperties", within the respective "*Coefs" section.
3. Then used like this:
   

       const scalar t = this->db().time().timeOutputValue();
       fvPatchField<Type>::operator==(uniformValue_->value(t));

   • Although in your case, it would be something like:
     

     visc->value(strainRate[celli])

4. Don't forget to include the header file:
   

   #include "Function1.H"

5. In the "transportProperties" file, you will need something like what's described here: http://openfoam.org/release/2-1-0/bo...ime-dependent/ - possibly this:
   

   viscTable     table
   (
       (0.0     0.014)
       (0.125   0.0123715)
       (0.25    0.011782)
   ...
       (????  0.00409976)
   );

If you still have trouble implementing it, please do the following steps, so it's easier to help you:

1. Provide the source code by following these steps:
   1. Run inside the source code folder of your custom library:
      

      wclean all

   2. Then go to the parent folder and package the source code folder, e.g. if the folder is named "splineTransport":
      

      tar -czf splineLib.tar.gz splineTransport

   3. Then attach the file "splineLib.tar.gz" to your next post.
2. Then we either need a test case, or instructions on how to change a tutorial in OpenFOAM to use your transport model.

Best regards,
Bruno

Dear Santos,

I am trying to simulate rising bubble in a solution that its density, viscosity nad surface tension are chaning with the concentration of solvent. I am using interFoam and I would like to implement my own correlations for calculating density, viscosity and surfance tension. I am new in OpenFoam and I am looking for a tutorial or any guidance to start it. Could you please help me or share any tutorial if you have for this problem?

Thanks and best regards,
Sadra

[sadra2003]

Originally Posted by Svensen

Hi, I'm trying to implement a precise viscosity model from experimental measurements.

I've created a folder "Spline" and two files "Spline.C" and "Spline.H".
I've redefined calcNu() method in the following was:

Foam::tmp<Foam::volScalarField>
Foam::viscosityModels::Spline::calcNu() const
{
    volScalarField strain = strainRate();
     volScalarField nu = strain;
     
//for each element of a field
     for (unsigned i=0; i<strain.size(); i++){
         double n = strain[i]; //get a strain-rate
    
        const double dn = 250/sizeof(visc);
        n /= dn; //scale it to match an index of array
    
/*visc array includes 2000 values of measured viscosity*/
        unsigned x1 = floor(n);
        if (x1 < 1) x1 = 0; //check minimum value
        if (x1 >= sizeof(visc)) x1 = sizeof(visc)-2; //check maximum value
        
        unsigned x2 = x1 + 1;
    
        if (x1 != x2){
            double y1 = visc[x1];
            double y2 = visc[x2];
        
            double k = y2 - y1; //linear interpolation
            double b = x2*y1 - x1*y2;
        
            nu[i] = k*n + b;
        }
        else{
            nu[i] = visc[x1];
        }
     }
    
    return nu;
}

It compiles with no error, however after start of pimpleFoam it exits with the following log:

#0  Foam::error::printStack(Foam::Ostream&) at ??:?
#1  Foam::sigFpe::sigHandler(int) at ??:?
#2  ? in "/lib/x86_64-linux-gnu/libc.so.6"
#3  Foam::viscosityModels::Spline::calcNu() const at ??:?
#4  Foam::viscosityModels::Spline::Spline(Foam::word const&, Foam::dictionary const&, Foam::GeometricField<Foam::Vector<double>, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<double, Foam::fvsPatchField, Foam::surfaceMesh> const&) at ??:?
#5  Foam::viscosityModel::adddictionaryConstructorToTable<Foam::viscosityModels::Spline>::New(Foam::word const&, Foam::dictionary const&, Foam::GeometricField<Foam::Vector<double>, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<double, Foam::fvsPatchField, Foam::surfaceMesh> const&) at ??:?
#6  Foam::viscosityModel::New(Foam::word const&, Foam::dictionary const&, Foam::GeometricField<Foam::Vector<double>, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<double, Foam::fvsPatchField, Foam::surfaceMesh> const&) at ??:?
#7  Foam::singlePhaseTransportModel::singlePhaseTransportModel(Foam::GeometricField<Foam::Vector<double>, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<double, Foam::fvsPatchField, Foam::surfaceMesh> const&) at ??:?
#8  ? at ??:?
#9  __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6"
#10  ? at ??:?

What can be wrong with my code ?

Dear Sevensen,

I am trying to simulate rising bubble in a solution that its density, viscosity nad surface tension are chaning with the concentration of solvent. I am using interFoam and I would like to implement my own correlations for calculating density, viscosity and surfance tension. I am new in OpenFoam and I am looking for a tutorial or any guidance to start it. Could you please help me or share any tutorial if you have for this problem?

Thanks and best regards,
Sadra